The present invention relates to a video transmission system for use in electronic monitoring or security systems for buildings in which the capture and transmission of still-frame video images from multiple video cameras may be controlled as required
It is well known in the security system art to include a video sub-system as part of a complete security systemxe2x80x94for example, multiple still-frame video cameras or closed circuit TV cameras distributed around premises to be protected for the visual monitoring of the premises. Commonly, particularly in the case of industrial security systems, all such video cameras are connected-to an on-site security office. The operation of the video cameras in such a system typically is automatically controlled to have the video image from each camera displayed on a dedicated monitor or to cycle the video outputs from multiple cameras to one or more monitors. Usually, a security guard can manually override the automatic system to monitor the output of any camera or cameras as desired.
In such systems, the video images from the cameras may or may not be recorded for possible review in the event some significant event occurs. In an extensive system, every camera may have associated hardware to record multiple images, which can be accessed if a security event later indicates that images from a particular camera should be examined.
Such industrial-type video systems are not suitable for smaller security systems, such as may be installed in many commercial or residential premises. A typical security system installed in such premises would have a number of alarms or similar devices distributed around the premises all connected to a main control panel. The control panel normally has telecommunication capability whereby an alarm or other reportable condition may be transmitted by telephone, cellular telephone or radio communication to a remote location, such as the police or now more commonly a central monitoring service. The central monitoring service receives and analyzes data sent from the panel and determines whether conditions are such that a security guard or the police should be dispatched to the premises and/or a report made to the owner who may be available at some other location.
Only limited video capability has heretofore been included in such smaller systems. For example, a single video camera monitoring what is considered to be the most important part of the premises (e.g. perhaps a front door) may be connected to the alarm panel via a suitable camera controller/interface device. An example of such a controller/interface device is a device made by Sur-Gard Security Systems Inc. and sold under the DOWNLOOK DLM-4 trade-mark. In such a system, upon identification of a reportable alarm condition, the control panel opens a communication channel with the central monitoring service, transmits the alarm data to the service and then transfers the communication channel to the controller/interface device which then downloads the video data (which may represent multiple sequential images, or frames, from the single camera) over the same channel to the service. A delay time from alarm to a first video frame capture may sometimes be selected or be programmed. In addition, the time between frame captures can usually be selectable or programmable as well.
Through a multiplexing arrangement, the above video system may be expanded to include multiple video sources, whereby upon recognition of an alarm condition, the image(s) from the multiple cameras are downloaded to the panel in a fixed and predetermined sequence.
The difficulty with all such prior art systems is that the selection of video images cannot be controlled according to relevant alarm or system status conditions or the needs of the central monitoring service or of a remotely located owner. For example, when an alarm is detected all the collected images from all of the video sources are downloaded to the central monitoring service. The receipt and display of all such video data can be quite time consuming at the central monitoring service, thus tying up telephone lines and thus possibly interfering with other, possibly very serious, incoming alarm calls. Even though the particular alarm (e.g. front door broken into) may suggest that only the video images from the camera covering that location need be examined, all of the images from all of the cameras must be received in order to receive the one image of potential interest. This is very inefficient, expensive (in terms of telecommunications time), and possibly extremely serious if an incoming life-threatening alarm call cannot be received because the lines are busy on another call downloading video data of questionable value. It would be advantageous to be more selective about transmitting video data that is more likely to be useful.
Another problem in conventional systems is that the alarm inputs are directly connected to the control panel, which upon receipt of an alarm signal processes the signal according to its predetermined algorithms to determine if a reportable alarm condition exists. Upon determination that a reportable alarm condition does exist, then the panel may initiate a trigger signal to commence the image capture and downloading process. This method of controlling the video downloading process inherently involves a number of delays.
First, because the alarm panel is looking for true alarm conditions and does not wish to trigger alarm responses in the event of a false alarm, typically there is built-in delay period during which an alarm signal from an alarm device will not be recognized as a valid alarm signal. The signal must exist for a predetermined minimum time period, typically half a second, before the alarm signal itself will be accepted by the panel as being a valid alarm signal from the alarm device in question. This is known as the xe2x80x9cdebouncexe2x80x9d time and this built-in delay is intended to allow the system to ignore transient conditions which normally are considered to be false alarms.
Second, there is the time required by the control panel to process the signal and determine that a valid reportable alarm condition exists.
Third, once such a reportable condition is determined to exist, the panel then initiates a trigger signal to the video system to initiate the capture and downloading process. There is an inherent bus latency period in establishing the communication from the panel to the video capture hardware.
Typically, the processing and bus latency times may amount to about one second. Thus, in total, delays from first receipt of an alarm signal to initiation of the video capture and downloading process may be as much as 1.5 or 2 seconds. These delays can make it very difficult to capture an image of a burglar. For example, if there is a break in at the front door, by the time the images of that location are captured, the burglar may be gone.
In large industrial or commercial security systems with many video cameras and large storage capacities, delays of this nature are not particularly important because the systems are producing images all the time which can later be accessed and reviewed if needed. However, in systems with smaller storage capacities, the problem can be quite severe.
According to one aspect, the invention is a video capture controller for selective capture of video images from a plurality of video cameras, the controller comprising multiple video signal inputs for receiving signals from video source devices, an arrangement for receiving input signals from a security system, a processor for processing the received input signals of such arrangement and comparing the received signals with a pre-determined set of possible received signals and, based thereon, determining a particular video capture protocol from a set of video capture protocols associated with the set of possible received signals, and a controller associated with the multiple video signal inputs and the processor, the controller having a video output, the controller selectively connecting the multiple video inputs with the video output based on the particular protocol determined by the processor.
According to another aspect, the invention is a process for capturing video images from multiple video sources in a system monitoring certain physical variables in or associated with a physical space, comprising monitoring the variables, identifying a set of conditions for such variables, selecting, in response to such set of conditions, a video image capture protocol from a pre-determined set of video image capture protocols each associated with at least one pre-determined set of conditions and capturing the video images in accordance with the selected protocol.
According to another aspect, the invention is a video capture controller for use in a system monitoring certain physical variables in or associated with a physical space, the system having multiple video sources, comprising a storage device storing a pre-determined set of video image capture protocols each associated with at least one pre-determined set of conditions of the variables, a receiver for receiving signals indicative of the condition of each such variable, a device for identifying a set of conditions for the variables, a retrieval device to retrieve from the storage device a specific video image capture protocol in response to the identified set of conditions, and, a video image capture device to capture the video images in accordance with said selected protocol.
According to yet a further aspect, the invention is a security system communications console for monitoring certain physical variables in or associated with a physical space, the system being adapted to receive signals from certain alarm detection devices distributed about the space, the signals being indicative of the condition of the variables being monitored by the devices, the console being adapted to connect to an external communication channel, comprising control panel for receiving said signals, for determining in response thereto whether a status report on the conditions of the variables should be made to an external location via the external communication channel, and, if so, for making said report, multiple video sources distributed about the space, a video capture controller comprising a storage device for storing a pre-determined set of video image capture protocols each associated with at least one pre-determined set of conditions for the variables, receiver for receiving from the alarm detection devices or from the panel signals indicative of the condition of each variable, device for identifying a set of conditions for the variables, retrieval device for retrieving from the storage device a specific video image capture protocol in response to the identified set of conditions, and, video capture device for capturing the video images in accordance with the selected protocol, and, video transmitter for transferring the captured video images to the external communication channel in the event that the panel makes a status report to an external location.
In yet a further aspect, the invention is a security system for monitoring certain physical variables in or associated with a physical space, the system being adapted to connect to an external communication channel, comprising alarm detection devices distributed about the space for generating signals indicative of the condition of the variables being monitored by the devices, control panel for receiving the signals, for determining in response thereto whether a status report on the conditions of the variables should be made to an external location via the external communication channel, and, if so, for making said report, multiple video sources distributed about the space, a video capture controller comprising a storage device for storing a pre-determined set of video image capture protocols each associated with at least one pre-determined set of conditions for the variables, receiver for receiving from the alarm detection devices or from the panel signals indicative of the condition of each variable, device for identifying a set of conditions for the variables, retieval device for retrieving from the storage device a specific video image capture protocol in response to the identified set of conditions, and, video image capture device for capturing the video images in accordance with the selected protocol, and, video transmitter for transferring the captured video images to the external communication channel in the event that the panel makes a status report to an external location.
In yet a further aspect, the invention is a video capture controller for capture of video images from at least one video source device, the controller comprising at least one video signal input for receiving signals from the at least one video source device, an arrangement for receiving input signals directly from at least one sensor in a security system and a processor for processing the received input signals of said arrangement and immediately triggering the capture of an image from said video source.